1. Field of the Invention
The embodiments of the invention provide a structure and method for a radiation hardened FinFET.
2. Description of the Related Art
Fin-type field effect transistors (FinFETs) are intrinsically relatively immune to various ionizing radiation-induced degradation effects. Further improvements to the basic FinFET structure are desired to further enhance the radiation hardened (rad-hard) qualities of FinFETs. Specifically, weak areas include the cap oxide on top of the fin, the buried oxide below the fin, and the gate edges.
Radiation exposure of isolation regions in complementary metal oxide semiconductor (CMOS) technology can lead to the development of parasitic leakage. This is because the lightly doped regions of silicon can become inverted from charge that is formed in the adjacent thick oxide regions. In shallow-trench isolation (STI), the upper parts of the trench sidewalls adjacent to silicon channels provide exposed regions that are susceptible to radiation damage.